Backfeed Protection Device - LEGRAND KEOR HPE Manuel De Fonctionnement

4.2

BACKFEED PROTECTION DEVICE

The KEOR HPE UPS is provided with voltage-free contacts which can be used to operate the shunt
trip coil of the external sectioning device; the external device is not part of the UPS supply and is
provided and installed at customer care.
To prevent any risk of hazardous voltage or hazardous energy present in the circuits supplying the
UPS after interruption of the input AC power , a backfeed insulating device should be installed
external to the UPS in the by pass input switchboard . This protection can be coupled with the by
pass line overcurrent protection using a MCCB equipped with a shunt trip coil and connected to UPS
applying the wiring diagram principle described in Figure 6, 6a, 6b.
In case of backfeed failure detected by the UPS , the UPS will send a signal to trip the MCCB to
isolate the UPS in order to protect the upstream distribution circuits .
The installer shall apply the following warning label on all primary power isolator that supplies the
UPS installed remote to the UPS.
- Then check for
The following table shows the main electrical characteristics of the external sectioning device.
Power (kVA)
Maximum operating voltage (Vac)
Minimum rated current (A)
Category
An isolator switch with integrated undervoltage release can beinstalled inside the UPS as an option.
32 OML46086 REV. I
Installation and start-up of KEOR HPE UPS 60÷160 kVA
Installation et démarrage de l'ASI KEOR HPE 60÷160 kVA
Installazione e avviamento KEOR HPE UPS 60÷160 kVA
Before working on this circuit
- Isolate uninterruptible power system (UPS)
hazardous
including the
Risk of Voltage Backfedd
Backfeed protection device
voltage between all terminals
protective earth
60 80
125 160
100 125
690
200 250
AC-1
160
315